(1) Field of the Invention
The present invention relates to image forming devices, and in particular, technologies for managing consumables used in image forming devices.
(2) Background
Image forming devices use various consumables. For example, an image forming device uses sheets stored in its paper cassettes as objects of printing. In such printing, devices of an electrophotographic type use toner, while devices of an inkjet type use ink such as pigment. A device of the electrophotographic type has movable members such as photoreceptor drums, an intermediate transfer belt, and transfer rollers, which are subject to wear caused by contact with other members and to fatigue resulting from vibration and the like. Accordingly, replenishment or replacement of these consumables at an appropriate time is expected in maintenance of image forming devices.
A typical image forming device is equipped with functions of notifying users or other electronic devices of the time for replenishment or replacement of consumables depending on consumption ratios of the consumables; such functions serve as support for management of the consumables. More specifically, a typical image forming device monitors one or more parameters that quantitatively indicate operational statuses of the device, such as the number of sheets printed, the amount of toner consumed, the number of jobs processed, and operating time. Based on values of these parameters, the device estimates consumption ratios of the consumables. When any of the estimated values indicates a need for replenishment or replacement of a consumable, such as paper or toner shortage, or an upcoming end of an expected service life of a movable member, the image forming device then notifies a user of the replenishment or replacement by display on an operation screen, or makes a request for the replenishment or replacement to an external management server. See, for example, JP 2002-300308.
Furthermore, JP 2014-092729, JP 2014-091298, JP 2014-052697, and JP 2012-128237 disclose a system for predicting the time of replenishment or replacement of consumables from changes in operating status of an image forming device. More specifically, this system first acquires data on operational statuses of the image forming device at regular intervals, e.g., every hour or every day. This system next estimates from the history of operational statuses the rates at which the image forming device consumes consumables. These rates are hereinafter referred to as “consumption rates.” The system then uses the estimated values to predict the time for replenishment or replacement of consumables. Under condition that new consumables will be delivered before this predicted time, the system orders the new consumables, thus making is possible to reduce or even eliminate the time during which exhaustion of a consumable brings the image forming device to a standstill.